We propose to develop a low cost, light weight gas phase actinometer suitable for use as a personnel dosimeter for occupational, recreational, or theraputic exposure to potentially carcinogenic ultraviolet light. For the 200-315 nm region, a tube containing acetaldehyde vapor in air is worn in an exposed place. The methane produced is then analyzed after the end of the shift or after suspected exposure by a gas chromatographic technique, Dilute NO2 is used for the 315-400 nm range, and analyzed by chemiluminescence for the NO produced. These detectors make use of our experience in gas phase actinometry developed with NASA support for solar intensity and atmospheric chemistry measurements. The molecules chosen provide a very close match to the required spectral shape for the radiation exposure standards, particularly in terms of the sharp cutoff at long wavelengths. This eliminates any possible interference from abundant long wavelength photons. The proposed dosimeter appears to be very cost effective compared to more sophisticated electronic dosimeters for UVB recently developed by Davidson, et al., with support from the National Cancer Institute and the Environmental Protection Agency. In the process of developing this proposal, we determined that solar radiation out-of-doors can violate the recommended exposure in the 315-400 nm region by as much as a factor of ten.